Largely due to the lact of effective therapeutic agents, severe dry eye states have become a significant cause of visual morbidity in this country. The immediate objectives of this research are (1) to learn the mechanisms by which conjunctival mucins stabilize the tear film of albino rabbits, mokeys, and humans and (2) to investigate how the similarities and differences in the properties of rabbit and human mucins may affect tear film stability in the two species. With conjunctival mucins as the model, the long-term objective of this research is to identify the desirable attributes of a tear substitute for patients suffereing from dry eye syndromes. This research intends to establish a technique for isolating and fractionating mucins from the conjuctivas of albino rabbirs, monkeys, and humans. Column chromatography and gel electgrophoresis are central to the fractionation scheme. The results of a preliminary experiment suggest the existence of tree rabbit conjunctival mucins. Acting on the premise that each mucin serves a specific role in bringing stability to the tear film, this research examines the behavior of each mucin in aqueous solution, with emphasis on (1) its degree of hydration, (2) its hydrophobicity, (3) the shape it assumes in solution, and (4) how if interacts with the tear proteins albumin, globulin, and lysozyme. The techniques of rheology, sedimentation velocity and equilibrium, and fluorescence spectroscopy will be employed. By altering the composition of the medium in which mucin exists, this research seeks to learn the factors controlling the relative proportion of each conunctival mucin present in tears. The medium's composition will be varied by altering the pH and ionic strength, and by including specific ions and denaturing agents such as urea, guanidine HC1, sodium dodecyl sulfate and dithioreitol. By comparing the properties of conjunctival mucins with those adhering to the corneal surfaces, this research seeks to learn the pathway of disposition of conjunctival mucin upon its discharge from goblet cells. Finally, based on the results of this research we hope to: (1) design future experiments to investigate the characteristics of mucins in dry eye states including those induced by vitamin A deficiency and those associated with aging, autoimmune diseases, and prolonged exposure to smog, and (2) develop a strategy to manage the dry eye state.